In order to grasp a traffic state in a road, observation data of vehicles that pass the road is collected and behaviors of the vehicles are estimated based on the collected observation data.
For example, JP. 11-161894 discusses a device to estimate behaviors of vehicles by collecting observation data such as passing time and speed using sensors such as beacons by taking account of lighting timing of traffic lights.
The device estimates behavior of vehicles that at least the time information when passing an observation point match with observation data detected by a sensor.
JP 2005-242688 discusses a simulator that simulates behavior of a driver and physical behavior of a vehicle by taking account of influence of surrounding vehicles, traffic signals, railroad crossings and other factors that influence driving vehicles.
The device simulates behavior of a driver and physical behavior of a vehicle by using a vehicle model. The vehicle model includes behavior parameters such as target acceleration and a target speed. A position and speed of the vehicle are determined according to the behavior parameters.